What is an insulin pump and how does it help?

This page includes an overview of pumps; how it helps you achieve better control; why pump users like them; disadvantages and how to tell if insulin pump therapy might be right for you.

An insulin pump is really just a computerised syringe.



— cannula

— infusion set


— insulin pump



  • it consists of 3 components; a cannula, an infusion set and a pump
  • it is a little smaller than the palm of an adult’s hand; some brands are smaller than others
  • it delivers insulin every few minutes in tiny amounts, 24 hours a day
  • the insulin flows through a cannula which sits in the subcutaneous tissue (which is where you inject) and is changed by the pump user every 2 or 3 days
  • basal (background) insulin is programmed to meet your needs (this replaces Lantus/Levemir etc)
  • bolus insulin is delivered at the touch of a button to cover food or bring down a high blood glucose level
  • only rapid-acting insulin is needed and provides all your insulin requirements.

Note: insulin pumps do not measure blood glucose levels, but some pumps can read the signal from a separate glucose sensor.

A “tethered” pump uses a fine tube to connect the pump to the cannula; the pump is worn in a pocket or clipped to a belt (as shown above).

A patch pump or micro pump has no tubing or a very short tube, and the pump is usually stuck on to the skin.

How can a pump help?

Controlling blood glucose levels tightly takes motivation and commitment. Studies such as the Diabetes Control and Complications Trial (DCCT 1993) have shown this is the best way to prevent or delay complications of type 1 diabetes such as blindness, amputation, heart disease, and kidney failure. These cause pain, disability and are expensive to treat. A pump used well is an effective tool for maintaining blood glucose levels within the normal range and helping to keep pumpers healthier and in work.

A pump can help you gain tighter control of your diabetes. Pump users can easily adjust their insulin dose according to their own changing needs, thus minimising high and low glucose swings and the resulting long- term complications.

Because the pump delivers insulin continuously day and night, only rapid-acting insulin is necessary at rates designed to meet basal insulin requirements: this means that you don’t need meals at specific times. You may eat when you like, or not at all, without suffering hypos or hypers. You can also exercise without risking high or low blood glucose levels promoting better health and well-being.

Pumps deliver insulin much more precisely than any available pen or syringe. Basal rates are adjustable down to lower than a tenth of a unit per hour, depending on the make of pump. The tiny doses of Insulin from a pump are more consistently absorbed than a larger amount from an injection where it is sometimes not absorbed properly causing glucose levels to run low or high for several hours.

Injected long-acting insulin can be absorbed differently every day-sometimes too quickly, sometimes too slowly, and sometimes only in part. This leads to variable control. With a pump and rapid acting insulin continuously delivering in tiny drops, absorption is much more reliable and your diabetes more stable and predictable.

Why do pump users like them?

+ feel more in control
+ flexibility (eg lazy mornings, skip meals or eat late)
+ give food boluses in the most appropriate way, eg spreading it over 7 hours for a pizza
+ set a temporary basal increase or decrease when ill, having your cycle, or stressed
+ manage dawn phenomenon
+ only one needle every 2 or 3 days
+ easier to manage blood glucose levels around planned or spontaneous exercise
+ treat hypers with precise correction doses (from a tenth of a unit upwards)
+ treat hypos with just fast-acting carbohydrate
+ manage changing shift work patterns
+ manage tight control during pregnancy and pre-pregnancy
+ manage toddlers’ meal-time battles
+ keep good control through growth spurts and hormonal changes in adolescence
+ manage traveling across time zones

What are the disadvantages?

– being attached to something 24/7 (you can take it off for up to an hour for showers, sports, etc)
– increased risk of DKA (that’s why you need to test blood glucose levels at least 4 times a day)
– risk of site infections (especially if you leave the cannula in longer than the recommended 2 or 3 days)

Most experts and users agree that the advantages of pumping far outweigh the disadvantages.

Is it right for me?

You have to be motivated enough to use this tool properly. That means you:-
• mindfully manage your diabetes on a day to day basis
• count carbohydrates and adjust insulin doses
• check blood glucose levels at least 4 times a day
• check that your basal rates are correct by occasionally missing meals
• check your insulin-to-carbohydrate ratios

If you are struggling with highs and lows despite your best efforts on MDI, or you have frequent hypos that affect your day-to-day choices, then a pump may help you.

The national Insulin Pump Audit published in May 2013 suggests that just over 18,000 of us in the UK are using an insulin pump.

To find out how to get one, and whether the NHS will fund it for you,
see NHS funding for insulin pump therapy

One Response to What is an insulin pump and how does it help?

  1. Pingback: NaBloPoMo #26 – Diabetes month | Now.Here.Life.

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